This alien annual is widely scattered in cultivated fields and roadsides across temperate North America. It was first reported from Ky. in 1893 (Pr), as "tricolor var. arvensis Hook"; an associated coll may exist at MO. However, subsequent records date only from Becket (1956) or later. Without fresh flowers, arvensis is sometimes hard to distinguish from rafinesquei (Sm, F, Cr); 2n = 34 in both species, but hybrids have not been documented. In addition to their distinctively short petals, about equalling sepals or less (versus longer), flowers of arvensis are strictly open-pollinated (versus often cleistogamous in rafinesquei), and creamy-white or pale yellow to occasionally purplish-tipped (versus pale yellow to deep blue). Also, its stipules are pinnately laciniate (versus palmately pectinate), with the enlarged upper lobes oblanceolate (versus narrowly spathulate) and, like the cauline leaves, crenate-serrate (versus entire or nearly so).